I think it would be really interesting to see the most viewed pages for a given year, sort of like a reflection of the major events, topics, etc. that brought users to the wiki. Is it feasible to add a yearly endpoint? It seems this would comparatively be inexpensive in terms of storage. Going by the endpoint for monthly stats, the yearly could simply be GET /metrics/pageviews/top/{project}/{access}/{year}/all-months/all-days.
UPDATE: according to a recent test, our bigger cluster also means this is relatively cheap to compute: T211827#4847998. Specifically, to make this more generic, instead of https://phabricator.wikimedia.org/P7945$14 we could compute total views and total distinct articles per wiki for a specific day or week. Using that and the pigeonhole principle, we should be able to come up with a pretty robust filter to ignore relatively low traffic.